1. Field of the Invention
This invention relates to an improved hepatic graft preservative composition and an improved method for viable preservation of the hepatic graft. More particularly, this invention relates to a viable liver preservative composition comprising an ascorbyl tocopheryl phosphate compound or a pharmacologically acceptable salt thereof and a method for viable preservation of the hepatic graft which comprises using said compound or salt.
2. Description of the Prior Art
For a successful organ transplantation, the organ resected from a donor must be kept functionally intact until it has been transplanted into a recipient. Each kind of organ has its own characteristics and, hence, requires a unique approach towards viable storage. However, the preservation principles applicable to all organs in common are to suppress metabolic consumption and preserve tissue ATP levels.
For the viable preservation of the liver for transplantation, there are two methods, namely the "simple cold storage method", which consists of initial perfusion with a preservative solution at 4.degree. C. and subsequent immersion in a similar cold preservative solution and the "continuous hypothermic perfusion storage method", which involves the use of a machine. Clinically, however, the simple cold storage method using a preservative solution is generally employed. As the liver preservative, University of Wisconsin (UW) solution is generally employed. However, this solution has the disadvantage that the reduced glutathione contained as an active ingredient is very labile and easily oxidized in aqueous medium and, therefore, must be extemporaneously added, thus complicating the procedure. Moreover, UW solution is viscous and cannot be easily buffered so that it is not fully satisfactory for preservation of the hepatic graft. Moreover, with the conventional preservative solutions including said UW solution, hepatocytes tend to be damaged for some reasons or other so that deterioration of liver function cannot be successfully prevented.
Therefore, research and development efforts are being made in earnest for developing an improved hepatic graft preservative solution free from the above-mentioned disadvantages and insuring good graft preserving effects.
In the course of their ceaseless research into the pharmacology of ascorbyl tocopheryl phosphate compounds, the inventors of the current application discovered that these compounds have an inhibitory effect on microcirculation disorders of the liver and are useful for the viable preservation of the liver isolated for transplantation. This discovery was followed by further studies which have resulted in the development of this invention.